The disclosure covers and elevated train station with platform, particularly for an inner city transit system.
Such an elevated train station has been disclosed in the study made by DEMAG and Messerschmitt-Boelkow-Blohm dated 1972. The platforms of this station are supported at each end by girders, as is usual for pedestrian bridges or similar structures. In densely populated inner cities, however, it is not always possible to find sufficient space for the girders of elevated train stations due to the arrangement of streets and sidewalks.
It is the object of the present invention to design an elevated train station in such a fashion that it may be erected in all locations of a transit system where stations are in order without interference and/or major changes in streets and sidewalks. This is solved by supporting the platform of the elevated train station with one girder only. A platform for short distance transit systems being approximately 10 to 12 meters in length, the arrangement stays within a range permitting the use of only one girder to transmit load and possible pitching moments and wind pressures onto the foundation. Such a single girder may thus be erected on a traffic island, a sidewalk or sidewalk corner without affecting pedestrian and automobile traffic any more than absolutely necessary. Further space required for any additional girders might be located in the middle of traffic lanes. When erecting a single girder elevated train station on a traffic island, the station is, in most cases, far enough removed from the nearest buildings, as not to infringe upon the rights of their inhabitants and/or owners. The ends of the elevated train station are located above the streets. Depending upon the course of the rail, the platform may be attached to the rail girder with additions as required.
A staircase leading to the platform may be attached to the girder. The girder itself may be designed as an elevator shaft. The elevator may be installed later on if it proves to be necessary only during the course of operation. A cantilever beam may be attached on the girder under which to arrange the platform with its roof. The platform is attached to the roof at its ends via end walls, and at the back by means of suspension bars.
One advantage of this type of elevated train station is that the structural groups manufactured in light-weight construction can be delivered to the construction site as prefabricated parts for quick assembly there. No time-consuming erection of construction fence and auxiliary stairs is needed. Traffic is only affected for a very short period of time, sometimes only for the duration of a night when traffic is slow.
If local conditions permit, the staircase is attached to the girder on the side opposite the platform thus becoming a countermoment to take some of the load off the girder and the foundation. The girder, staircase and cantilever beam have small dimensions and may be transported on a normal truck. Only the platform complete with roof requires a special truck of the relatively small service load of 10 tons approximately on account of its dimensions. One of the smaller mobile cranes will suffice for assembly of the elevated train station. If an elevated train station with superimposed stations is involved, the girder of the upper platform is preferably attached to the cantilever beam of the lower platform. Thus the platforms are uniformly designed; it is only necessary to reinforce the lower cantilever beam to receive the load of the upper platform. To decrease the pitching moment, the platforms may project into opposite directions from the girder. The upper part of the girder is then fitted with another staircase.
In further development of the invention, the roof of the platform is designed as a wing or suspension assembly and attached under the cantilever beam. The roof consists of an upper plate whose longitudinal sides are shaped as an inverted U just above head height. Below the plate U-shaped cut-out cross stays extending to the ends of the inverted U are provided, the lower edges of such cross stays being interconnected via a flat longitudinal profile or plate and with the longitudinal sides of the roof plate. Thus, the roof forms a stable support. This shape not only results in a statically favorable support element, but functionally it has the advantage that the space above the platform is of sufficient height to permit the handling of long pieces, e.g. skis. This inverted U-shaped roof reduces the open portion of the platform to head level so that there is enough protection against snow and rain in the rear part or open side of the roof-covered platform. Furthermore, the overhanging roof edge near the platform serves as a warning when handling long objects while entering the vehicles.
To reinforce the roof, the area of the cantilever beam is, on the inside next to the bent-down front and rear longitudinal sides of the roof plate, fitted with one reinforcement stay each penetrating the roof plate on top and provided with one screw-on flange each for the cantilever beam. The ends of the reinforcement stays may be bevelled and, starting from the cantilever beam, extends to one or two cross stays. The reinforcement stays are welded with the longitudinal profiles or plates and form a stable box profile together with the roof plate and its bent-down longitudinal edges.
The end walls mentioned previously are interconnected at the platform side below the floor of the platform by means of a floor longitudinal beam. The end walls are so stable that they prevent lateral displacement of the floor vs. the roof. The rear of the roof-covered platform, at the bent-down or overhanging edge of the roof, is fitted with suspended bars for the rear ends of floor cross beams, their front ends being attached to the floor longitudinal beam. The suspended bars are equipped with contact surfaces or frames to attach glass panes and represent, furthermore, the simplest and easiest structural means of supporting the floor cross beams in the rear wall area. To prevent longitudinal displacement of the floor vs. the roof a portion of the rear side wall and a front wall area of the roof-covered platform may be equipped with stays. The space between the walls equipped with stays, particularly the end wall, is suitable as a maintenance and/or machine room, which should be present at any elevated train station. This room is preferably located at that side of the roof-covered platform which projects the least past the girder, thus forming a countermoment for the longer portion of the platform.
In further development of the invention, the roof described above is provided with a raised circumferential edge or rim protruding past the roof plate. Within the space surrounded by the raised edge, the roof is provided with a water retention area connected to a gutter pipe in water-tight connection, such pipe going through the maintenance and machine room towards the girder, thus not taking away from the appearance of the elevated train station. The raised edge consists of a rim directed upward from the roof plate whose edge, as mentioned before, overhangs. The roof plate may be fitted at the interior of the rim with suspension eyelets which facilitate suspension from the crane during assembly. The suspension eyelets are attached near the four corners of the roof, therefore in an especially stable area, so that no reinforcement of the roof is required for the suspension eyelets. Furthermore, being arranged at the interior of the rim they do not interfere with the optical picture and do not have to be removed after assembly.
The floor of the roof-covered platform is preferably made of sound deadening light concrete, e.g. prefabricated elements which are placed on the edge of the floor longitudinal beams and cross beams.
In stations for suspended vehicles the invention provides the edge of the floor longitudinal beam with a device serving as protection against falling, such protective device being essentially horizontal and protruding beyond the platform edge; it consists preferably of a thin steel mesh attached to a frame. The thin steel mesh, giving the appearance of being too weak to stand on, has the advantage of not being stepped on intentionally. A seemingly strong protective device would seem like an invitation to willful persons to step on so that an additional protection would have to be present.
The staircase preferably consists of two stair wells or flights, their sections being connected in the area of an intermediate landing, and upper and lower ends being attached to the girder. The staircase sections together with the girder form a triangle stable in itself, only tensile and compressive forces occurring in its parts in the manner of a lattice. The cross sections of the staircase each form a supporting profile spanning the stairs and well, the side walls of such supporting profile being provided with an opening at the height of the intermediate landing of one flight for admission to the intermediate landing of the other flight. The supporting profile of each staircase section consists of a U-shaped upper belt or frame and a U-shaped lower belt or frame, their edges directed towards each other and connected to each other. As no great forces occur, the belts alone are strong enough to receive the tensile and compressive forces of the lattice, and due to their connection with each other they are capable of receiving the load of the staircase. The upper and lower belts or frame are connected with each other via vertical rods which are designed as attachment moldings or frames for glass panes. The sections of the staircase, after being screwed in place at the level of the intermediate landing and after being screwed to the girder, form a very solid structural unit with little empty weight, which can be used right after the start of the assembly. To make assembly easier, the upper belt is provided with suspension eyelets, the same as the roof plate of the platform.
The girder consists of four corner columns with strutting or cross-bracing which may be covered. The struts prevent outward bending of the girder corner columns which are subject to eccentric load, and which accommodate the elevator shaft. The strutting results in a bracing of the girder which roughly corresponds to that of a closed box profile. Thus sufficient stability is guaranteed even if the platform projects very far. The girder is covered to protect it from atmospheric conditions. The covered or lining consists partially, e.g. on one side, of transparent material, so that people in the elevator retain eye contact with their surroundings. The rain gutter mentioned previously leads from the roof-covered platform through the girder and may end in the sewer system or may emerge from the girder above ground, depending upon circumstances. The girder contains all supply lines leading from the foundation to the platform.
Preferably, the elevator shaft goes so far below the ground, that a space is left below the elevator to accommodate an elevator hoisting mechanism, for a hydraulic installation with telescope cylinders. Such installation needs little maintenance and is of low structural height. The space for the elevator hoisting mechanism may be entered even while the elevator is lowered, from an inspection shaft located beneath the landing in front of the first stair.
The girder must be anchored on a tilt-resistant foundation, preferably a drill pole foundation. This foundation structure offers room between the individual poles for an easily accessible location of sewage connections and the elevator hoisting mechanism. The cantilever beam is made of a stable box profile provided with cross stays to transmit bending and torsional stress. It may be so long that there is a space left between girder and platform. This may be necessary if due to local conditions the girder cannot stand directly to the platform and the course of the elevated rail does not permit moving the platform.
During assembly, the cantilever beam may first be attached to the roof-covered platform and together with the latter attached to the girder within a very short period of time. The roof-covered platform is connected to the cantilever beam by means of screws via its screw flanges. By means of additional screws, the cantilever beam is attached to a cover plate of the girder. The sequence of assembly may vary. It is advisable to finish first the less accessible screw connections between cantilever beam and roof of the platform or cantilever beam and girder, so that the use of a crane during the final steps of assembly is kept to a minimum. In the type of construction chosen it is recommended to provide surface protection for all parts of the elevated train station while still in the shop. Damage to the surface protection during transport and assembly is not to be expected; should some damage occur nevertheless, it may be removed easily and quickly.
For a further understanding of the invention, reference is made to the drawings, showing illustrative examples of the elevated railway platforms of the invention.